The Method of Curing Activated Sludge Treatment Process during Shutdown

2016 ◽  
Vol 70 (5) ◽  
pp. 482-486
Author(s):  
Kenji Hayashi
Keyword(s):  
Activated Sludge ◽  
Treatment Process ◽  
Sludge Treatment

Activated Sludge Treatment of Ethoxylate Surfactants at High Industrial Use Concentrations

1988 ◽  
Vol 20 (11-12) ◽  
pp. 125-130 ◽  
Author(s):  
J. P. Salanitro ◽  
G. C. Langston ◽  
P. B. Dorn ◽  
L. Kravetz
Keyword(s):  
Activated Sludge ◽  
Fathead Minnow ◽  
Treatment Process ◽  
Aquatic Toxicity ◽  
Alcohol Ethoxylate ◽  
Sludge Treatment ◽  
Nonylphenol Ethoxylate ◽  
Incomplete Removal ◽  
Industrial Use ◽  
Bod Removal

The primary degradation of a linear alcohol ethoxylate (AE) and a branched nonylphenol ethoxylate (NPE) was investigated in bench-scale activated sludge units treating a synthetic sewage feed. Biotreaters were gradually adapted to 10-100 mg/ℓ surfactant and effluents monitored for loss of nonionic ethoxylate, foaming, feed BOD removal, nitrification and biosolids growth. Both surfactants were degraded at influent doses of 10-40 mg/ℓ. Substantial BOD breakthrough, loss of nitrification, aerator foaming and incomplete removal of the NPE surfactant occurred when fed at 80 and 100 mg/ℓ while the unit treating AE was unaffected by high surfactant levels. Comparative aquatic toxicity of the biotreated waste at high surfactant levels indicated that the NPE effluent was acutely toxic (EC50, 7-15% effluent) to the fathead minnow and Daphnia while that of the AE unit was non-toxic (EC50, > 100% effluent) to these same species. These studies indicate that the treatment of wastes containing high levels of NPE ethoxylates may adversely impact an activated sludge process in incomplete degradation and foaming, impaired BOD removal, loss in nitrification and the formation of toxic effluents. AE surfactants, however, undergo extensive microbial degradation and cause little or no impact on the activated sludge treatment process.

Control of activated sludge treatment process using pre-compensated multi-variable quantitative feedback theory-based controller

2021 ◽  
pp. 014233122110390
Author(s):  
Sandipan Prasad Chakravarty ◽  
Aniket Roy ◽  
Prasanta Roy
Keyword(s):  
Activated Sludge ◽  
Treatment Process ◽  
Waste Water Treatment ◽  
Measurement Data ◽  
Treatment Plant ◽  
Ammonium Ion ◽  
Waste Water Treatment Plant ◽  
Quantitative Feedback Theory ◽  
Sludge Treatment ◽  
Control Scheme

This paper deals with the design of a pre-compensated multi-variable quantitative feedback theory (QFT)-based fully populated matrix controller for an activated sludge treatment process (ASTP) of a waste water treatment plant (WWTP). The regulation of the concentration of biochemical oxygen demand ([Formula: see text]) and ammonium-ion ([Formula: see text]) is the control objective. The plant dynamics are obtained using physical laws available in the literature. The parametric uncertainty is quantified from the measurement data obtained from a real ASTP of an oil refinery. The model is duly cross-validated. A novel technique is proposed to design a pre-compensator that will enhance the diagonal dominance of the plant transfer function matrix. A diagonal controller and a pre-filter, are then designed using a sequential multi-input multi-output (MIMO) QFT-based methodology to meet a set of performance specifications such as relative stability, disturbance rejection, robust tracking and so forth. The simulation results validate the effectiveness of the proposed control scheme. A comparative analysis with reported works shows that the proposed control scheme outperforms some of the reported control strategies.

scholarly journals Biocompatibility and biodegradability of polyacrylate/ZnO nanocomposite during the activated sludge treatment process

PLoS ONE ◽  
2018 ◽  
Vol 13 (11) ◽  
pp. e0205990 ◽  
Author(s):  
Chao Zhu ◽  
Huiqin Wang ◽  
Zarak Mahmood ◽  
Qing Wang ◽  
Hongrui Ma
Keyword(s):  
Activated Sludge ◽  
Treatment Process ◽  
Sludge Treatment

Chlorinated Phenolics Removal from Bleached Kraft Mill Wastewater in Three Secondary Treatment Processes

1994 ◽  
Vol 29 (5-6) ◽  
pp. 177-187 ◽  
Author(s):  
E. R. Hall ◽  
W. G. Randle
Keyword(s):  
Activated Sludge ◽  
Treatment Process ◽  
Operating Conditions ◽  
Secondary Treatment ◽  
Threshold Values ◽  
Sludge Treatment ◽  
Treatment Processes ◽  
Kraft Mill Effluent ◽  
Kraft Mill ◽  
Removal Efficiencies

Laboratory-scale activated sludge (AS), facultative stabilization basin (FSB) and aerated stabilization basin (ASB) processes were operated in parallel treating bleached kraft mill effluent under controlled SRT and temperature conditions, to assess the chlorinated phenolics removal efficiencies attainable in each. The structure and extent of chlorination of the chlorophenolic compounds monitored appeared to contribute to the differing removal efficiencies observed. Under most operating conditions, treatment process effluents contained chronically toxic levels of pentachlorophenol-equivalent toxicity (TEQ). A companson of the results obtained from the FSB, ASB and AS processes indicated that, under most operating conditions, chlorophenolics removal in low rate treatment systems is superior to that in a higher rate activated sludge treatment process. However, it was also observed that operation at long SRT and moderate temperature permitted enhanced removal of chlorophenolics and reduced TEQs to less than threshold values, in all three treatment processes.

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